Typically aircraft communicate directly from the aircraft to a ground station. Due to limits of aircraft communication ranges, an aircraft typically has to be within approximately 100-150 miles of a very high frequency (VHF) ground station to communicate. So to communicate during a flight of any significant distance, a large number of ground stations are needed. Companies which set up the ground stations then charge airlines a fee for use of the ground stations and ground communications networks to communicate data to the intended destination. As a result, airlines have an added cost to operations in order to communicate between aircraft and a ground destination not within range of a given aircraft.
Alternative methods of aircraft communication have been developed, such as through the use of high frequency (HF) and satellite communication systems. Such systems are particularly useful for areas where VHF ground stations are not available, such as over an ocean. However, such HF and satellite systems can also result in a large cost to the airlines due to the expense of launching and maintaining satellites and operating ground stations and networks. In addition, HF systems are subject to interference and disturbance due to solar activity.